UNIT 12 : PLANT AND ANIMAL NUTRITION YEAR 8, 2013 …12+-+Plant+and... · UNIT 12 : PLANT AND...
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UNIT 12 : PLANT AND ANIMAL NUTRITION YEAR 8, 2013 MSPSBS/LSS/Unit 12/2013 Page 1 of 6 12.1 – PHOTOSYNTHESIS At the end of the lesson, you should be able to: define photosynthesis as the process by which plants manufacture food using carbon dioxide and water in the presence of sunlight and chlorophyll. state the word equation for photosynthesis. Green plants are at the beginning of all food chains. Plants are known as ' producers ' because only plants make their own food by a process called “photosynthesis ” [Photo means light and synthesis means to combine] Animals depend directly or indirectly on green plants for food. Green plants need sunlight to produce food. They 'capture' the sun's light energy using the chlorophyll in their leaves and use it to make a sugar called glucose . Glucose is a simple sugar and is needed to provide energy for the plant. PHOTOSYNTHESIS is the process in which green plants make food (glucose) using raw materials such carbon dioxide and water with the help of sunlight and chlorophyll. All organisms require the energy from the Sun. I use the energy from the Sun to Sunbath my body to give me a nice brown colour and my mother dries the clothes under the sun everyday. However, there are some living organisms such as green plants that make use of this solar energy to make their own food.
Transcript of UNIT 12 : PLANT AND ANIMAL NUTRITION YEAR 8, 2013 …12+-+Plant+and... · UNIT 12 : PLANT AND...
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 1 of 6
121 ndash PHOTOSYNTHESIS
At the end of the lesson you should be able to define photosynthesis as the process by which plants manufacture food using carbon dioxide and water in the
presence of sunlight and chlorophyll state the word equation for photosynthesis
Green plants are at the beginning of all food chains Plants are known as producers because
only plants make their own food by a process called ldquophotosynthesisrdquo
[Photo means light and synthesis means to combine] Animals depend directly or indirectly on green plants for food Green plants need sunlight to produce food They capture the suns light energy using the chlorophyll in their leaves and use it to make a sugar called glucose Glucose is a simple sugar and is needed to provide energy for the plant
PHOTOSYNTHESIS is the process in which green plants make food (glucose) using raw materials such carbon dioxide and water with the help of
sunlight and chlorophyll
All organisms require the energy from the Sun I use the energy from the Sun to Sunbath my body to give me a nice brown colour and my mother dries the clothes under the
sun everyday
However there are some living organisms such as green plants that make use of this solar energy to make their own food
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 2 of 6
How photosynthesis works
Plants can photosynthesize to make their own food
because they have chloroplasts (a disc-like structure) in the green parts of their leaves Inside these chloroplasts are green pigments called the chlorophyll
These chlorophylls are the ones which absorb the light energy from the sun and use it to change carbon dioxide and water into glucose and releases oxygen The glucose produced in the photosynthesis reaction is carried to other parts of the plant through the phloem vessels Glucose cannot be stored as it is very soluble therefore it is converted to starch and stored in the leaves
Oxygen is a waste product of photosynthesis which is released into the air through tiny pores under the leaves called stomata
Conditions needed for photosynthesis
Plants need 4 important factors in order to photosynthesize
1 light energy (from the sun) 2 chlorophyll (the green
substances in plant) 3 carbon dioxide (from the air) 4 water (from the soil)
Photosynthesis produces
1 glucose (converted to starch) 2 oxygen (a waste product or by-
product of photosynthesis)
Exchange of gases such as carbon dioxide water vapour and oxygen takes place
through the stomata of the leaves
Photosynthesis is a complex process (chemical reaction) which occurs in a series of steps However it can be summarized into a simple word equation like this
Light energy from the sun
Carbon dioxide + water ----------------------------------------gt glucose + oxygen Absorbed by chlorophyll
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 3 of 6
The following practical activities will investigate some of these factors listed above (1) LIGHT amp PHOTOSYNTHESIS Aim To show that light is necessary for photosynthesis
Conclusion Starch is produced only in areas that received light showing that light is necessary for photosynthesis (2) CHLOROPHYLL amp PHOTOSYNTHESIS
Aim To show that chlorophyll is necessary for photosynthesis
A variegated leaf (a leaf with green and non-green parts)
Conclusion Starch is made only in areas of the leaf with chlorophyll showing that chlorophyll is necessary for photosynthesis Only the green parts of the leaf make starch because the non-green parts have no chloroplast hence no chlorophyll
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 4 of 6
3) CARBON DIOXIDE (GASES) amp PHOTOSYNTHESIS
The presence of starch can be tested using lsquoiodine solutionrsquo which will turn from yellow to blue-black in colour when starch is present When testing the leaves from plant A amp B it is found that
In plant A In plant B
The leaves do not turn blue-black upon testing with iodine solution (the iodine solution remains yellow) It is concluded that STARCH IS ABSENT here
The leaves turn blue-black upon testing with iodine solution It is concluded that STARCH IS PRESENT
Therefore CARBON DIOXIDE must be present for photosynthesis to take place STARCH TEST IN A GREEN LEAF
To find out that food (starch) is really synthesized by green plants during photosynthesis we can do a test on a green leaf for starch Here are the steps necessary to carry out when testing a green leaf for starch
(1) Pick a small leaf Boil the leaf in a beaker of water to kill and soften it
(2) Heat the leaf again but in a test tube of alcohol The alcohol decolourizes the leaf Caution
Turn off the flame as alcohol burns easily
(3) Remove the decolourised leaf and put it in a beaker of hot water to soften it
(4) Place the soften leaf on a white tile and add a few drops of iodine solution to it Conclusion Starch is present if the leaf turns from yellow to dark blue-black
Both soda lime and sodium hydroxide solution absorbs carbon dioxide from the air
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 5 of 6
IMPORTANCE OF PHOTOSYNTHESIS
Mineral requirements of plants
Green plants make food by photosynthesis However for healthy growth plants also need minerals such as nitrates calcium phosphates and potassium These nutrients (absorbed as minerals dissolved in water) which plants take through their roots in the soil
The experiment below shows the effect of minerals on plant growth
Photosynthesis is the only natural process that
can convert light energy into chemical energy
enables green plants to make food
releases oxygen into the atmosphere and removes carbon dioxide from the atmosphere In this way photosynthesis keeps the proportion of oxygen and carbon dioxide in the atmosphere balanced
Glucose to all parts of the
plant
[Yellow leaves]
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 6 of 6
It is found that
1 Seedlings are grown in the test tube containing different minerals solutions
2 After a few weeks the seedlings look quite different Only in the first tube with all minerals present the seedling grows well
3 This experiment demonstrates the importance of certain elements in healthy plant growth
4 Plants grow well in soil which contains minerals Only small quantities of the mineral are needed for healthy growth
In smaller quantities plants also need minerals such as
Magnesium Iron Calcium Sulphur
A healthy tomato plant Tomato plant suffering from potassium deficiency
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 2 of 6
How photosynthesis works
Plants can photosynthesize to make their own food
because they have chloroplasts (a disc-like structure) in the green parts of their leaves Inside these chloroplasts are green pigments called the chlorophyll
These chlorophylls are the ones which absorb the light energy from the sun and use it to change carbon dioxide and water into glucose and releases oxygen The glucose produced in the photosynthesis reaction is carried to other parts of the plant through the phloem vessels Glucose cannot be stored as it is very soluble therefore it is converted to starch and stored in the leaves
Oxygen is a waste product of photosynthesis which is released into the air through tiny pores under the leaves called stomata
Conditions needed for photosynthesis
Plants need 4 important factors in order to photosynthesize
1 light energy (from the sun) 2 chlorophyll (the green
substances in plant) 3 carbon dioxide (from the air) 4 water (from the soil)
Photosynthesis produces
1 glucose (converted to starch) 2 oxygen (a waste product or by-
product of photosynthesis)
Exchange of gases such as carbon dioxide water vapour and oxygen takes place
through the stomata of the leaves
Photosynthesis is a complex process (chemical reaction) which occurs in a series of steps However it can be summarized into a simple word equation like this
Light energy from the sun
Carbon dioxide + water ----------------------------------------gt glucose + oxygen Absorbed by chlorophyll
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 3 of 6
The following practical activities will investigate some of these factors listed above (1) LIGHT amp PHOTOSYNTHESIS Aim To show that light is necessary for photosynthesis
Conclusion Starch is produced only in areas that received light showing that light is necessary for photosynthesis (2) CHLOROPHYLL amp PHOTOSYNTHESIS
Aim To show that chlorophyll is necessary for photosynthesis
A variegated leaf (a leaf with green and non-green parts)
Conclusion Starch is made only in areas of the leaf with chlorophyll showing that chlorophyll is necessary for photosynthesis Only the green parts of the leaf make starch because the non-green parts have no chloroplast hence no chlorophyll
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 4 of 6
3) CARBON DIOXIDE (GASES) amp PHOTOSYNTHESIS
The presence of starch can be tested using lsquoiodine solutionrsquo which will turn from yellow to blue-black in colour when starch is present When testing the leaves from plant A amp B it is found that
In plant A In plant B
The leaves do not turn blue-black upon testing with iodine solution (the iodine solution remains yellow) It is concluded that STARCH IS ABSENT here
The leaves turn blue-black upon testing with iodine solution It is concluded that STARCH IS PRESENT
Therefore CARBON DIOXIDE must be present for photosynthesis to take place STARCH TEST IN A GREEN LEAF
To find out that food (starch) is really synthesized by green plants during photosynthesis we can do a test on a green leaf for starch Here are the steps necessary to carry out when testing a green leaf for starch
(1) Pick a small leaf Boil the leaf in a beaker of water to kill and soften it
(2) Heat the leaf again but in a test tube of alcohol The alcohol decolourizes the leaf Caution
Turn off the flame as alcohol burns easily
(3) Remove the decolourised leaf and put it in a beaker of hot water to soften it
(4) Place the soften leaf on a white tile and add a few drops of iodine solution to it Conclusion Starch is present if the leaf turns from yellow to dark blue-black
Both soda lime and sodium hydroxide solution absorbs carbon dioxide from the air
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 5 of 6
IMPORTANCE OF PHOTOSYNTHESIS
Mineral requirements of plants
Green plants make food by photosynthesis However for healthy growth plants also need minerals such as nitrates calcium phosphates and potassium These nutrients (absorbed as minerals dissolved in water) which plants take through their roots in the soil
The experiment below shows the effect of minerals on plant growth
Photosynthesis is the only natural process that
can convert light energy into chemical energy
enables green plants to make food
releases oxygen into the atmosphere and removes carbon dioxide from the atmosphere In this way photosynthesis keeps the proportion of oxygen and carbon dioxide in the atmosphere balanced
Glucose to all parts of the
plant
[Yellow leaves]
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 6 of 6
It is found that
1 Seedlings are grown in the test tube containing different minerals solutions
2 After a few weeks the seedlings look quite different Only in the first tube with all minerals present the seedling grows well
3 This experiment demonstrates the importance of certain elements in healthy plant growth
4 Plants grow well in soil which contains minerals Only small quantities of the mineral are needed for healthy growth
In smaller quantities plants also need minerals such as
Magnesium Iron Calcium Sulphur
A healthy tomato plant Tomato plant suffering from potassium deficiency
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 3 of 6
The following practical activities will investigate some of these factors listed above (1) LIGHT amp PHOTOSYNTHESIS Aim To show that light is necessary for photosynthesis
Conclusion Starch is produced only in areas that received light showing that light is necessary for photosynthesis (2) CHLOROPHYLL amp PHOTOSYNTHESIS
Aim To show that chlorophyll is necessary for photosynthesis
A variegated leaf (a leaf with green and non-green parts)
Conclusion Starch is made only in areas of the leaf with chlorophyll showing that chlorophyll is necessary for photosynthesis Only the green parts of the leaf make starch because the non-green parts have no chloroplast hence no chlorophyll
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 4 of 6
3) CARBON DIOXIDE (GASES) amp PHOTOSYNTHESIS
The presence of starch can be tested using lsquoiodine solutionrsquo which will turn from yellow to blue-black in colour when starch is present When testing the leaves from plant A amp B it is found that
In plant A In plant B
The leaves do not turn blue-black upon testing with iodine solution (the iodine solution remains yellow) It is concluded that STARCH IS ABSENT here
The leaves turn blue-black upon testing with iodine solution It is concluded that STARCH IS PRESENT
Therefore CARBON DIOXIDE must be present for photosynthesis to take place STARCH TEST IN A GREEN LEAF
To find out that food (starch) is really synthesized by green plants during photosynthesis we can do a test on a green leaf for starch Here are the steps necessary to carry out when testing a green leaf for starch
(1) Pick a small leaf Boil the leaf in a beaker of water to kill and soften it
(2) Heat the leaf again but in a test tube of alcohol The alcohol decolourizes the leaf Caution
Turn off the flame as alcohol burns easily
(3) Remove the decolourised leaf and put it in a beaker of hot water to soften it
(4) Place the soften leaf on a white tile and add a few drops of iodine solution to it Conclusion Starch is present if the leaf turns from yellow to dark blue-black
Both soda lime and sodium hydroxide solution absorbs carbon dioxide from the air
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 5 of 6
IMPORTANCE OF PHOTOSYNTHESIS
Mineral requirements of plants
Green plants make food by photosynthesis However for healthy growth plants also need minerals such as nitrates calcium phosphates and potassium These nutrients (absorbed as minerals dissolved in water) which plants take through their roots in the soil
The experiment below shows the effect of minerals on plant growth
Photosynthesis is the only natural process that
can convert light energy into chemical energy
enables green plants to make food
releases oxygen into the atmosphere and removes carbon dioxide from the atmosphere In this way photosynthesis keeps the proportion of oxygen and carbon dioxide in the atmosphere balanced
Glucose to all parts of the
plant
[Yellow leaves]
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 6 of 6
It is found that
1 Seedlings are grown in the test tube containing different minerals solutions
2 After a few weeks the seedlings look quite different Only in the first tube with all minerals present the seedling grows well
3 This experiment demonstrates the importance of certain elements in healthy plant growth
4 Plants grow well in soil which contains minerals Only small quantities of the mineral are needed for healthy growth
In smaller quantities plants also need minerals such as
Magnesium Iron Calcium Sulphur
A healthy tomato plant Tomato plant suffering from potassium deficiency
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 4 of 6
3) CARBON DIOXIDE (GASES) amp PHOTOSYNTHESIS
The presence of starch can be tested using lsquoiodine solutionrsquo which will turn from yellow to blue-black in colour when starch is present When testing the leaves from plant A amp B it is found that
In plant A In plant B
The leaves do not turn blue-black upon testing with iodine solution (the iodine solution remains yellow) It is concluded that STARCH IS ABSENT here
The leaves turn blue-black upon testing with iodine solution It is concluded that STARCH IS PRESENT
Therefore CARBON DIOXIDE must be present for photosynthesis to take place STARCH TEST IN A GREEN LEAF
To find out that food (starch) is really synthesized by green plants during photosynthesis we can do a test on a green leaf for starch Here are the steps necessary to carry out when testing a green leaf for starch
(1) Pick a small leaf Boil the leaf in a beaker of water to kill and soften it
(2) Heat the leaf again but in a test tube of alcohol The alcohol decolourizes the leaf Caution
Turn off the flame as alcohol burns easily
(3) Remove the decolourised leaf and put it in a beaker of hot water to soften it
(4) Place the soften leaf on a white tile and add a few drops of iodine solution to it Conclusion Starch is present if the leaf turns from yellow to dark blue-black
Both soda lime and sodium hydroxide solution absorbs carbon dioxide from the air
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 5 of 6
IMPORTANCE OF PHOTOSYNTHESIS
Mineral requirements of plants
Green plants make food by photosynthesis However for healthy growth plants also need minerals such as nitrates calcium phosphates and potassium These nutrients (absorbed as minerals dissolved in water) which plants take through their roots in the soil
The experiment below shows the effect of minerals on plant growth
Photosynthesis is the only natural process that
can convert light energy into chemical energy
enables green plants to make food
releases oxygen into the atmosphere and removes carbon dioxide from the atmosphere In this way photosynthesis keeps the proportion of oxygen and carbon dioxide in the atmosphere balanced
Glucose to all parts of the
plant
[Yellow leaves]
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 6 of 6
It is found that
1 Seedlings are grown in the test tube containing different minerals solutions
2 After a few weeks the seedlings look quite different Only in the first tube with all minerals present the seedling grows well
3 This experiment demonstrates the importance of certain elements in healthy plant growth
4 Plants grow well in soil which contains minerals Only small quantities of the mineral are needed for healthy growth
In smaller quantities plants also need minerals such as
Magnesium Iron Calcium Sulphur
A healthy tomato plant Tomato plant suffering from potassium deficiency
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 5 of 6
IMPORTANCE OF PHOTOSYNTHESIS
Mineral requirements of plants
Green plants make food by photosynthesis However for healthy growth plants also need minerals such as nitrates calcium phosphates and potassium These nutrients (absorbed as minerals dissolved in water) which plants take through their roots in the soil
The experiment below shows the effect of minerals on plant growth
Photosynthesis is the only natural process that
can convert light energy into chemical energy
enables green plants to make food
releases oxygen into the atmosphere and removes carbon dioxide from the atmosphere In this way photosynthesis keeps the proportion of oxygen and carbon dioxide in the atmosphere balanced
Glucose to all parts of the
plant
[Yellow leaves]
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 6 of 6
It is found that
1 Seedlings are grown in the test tube containing different minerals solutions
2 After a few weeks the seedlings look quite different Only in the first tube with all minerals present the seedling grows well
3 This experiment demonstrates the importance of certain elements in healthy plant growth
4 Plants grow well in soil which contains minerals Only small quantities of the mineral are needed for healthy growth
In smaller quantities plants also need minerals such as
Magnesium Iron Calcium Sulphur
A healthy tomato plant Tomato plant suffering from potassium deficiency
UNIT 12 PLANT AND ANIMAL NUTRITION YEAR 8 2013
MSPSBSLSSUnit 122013 Page 6 of 6
It is found that
1 Seedlings are grown in the test tube containing different minerals solutions
2 After a few weeks the seedlings look quite different Only in the first tube with all minerals present the seedling grows well
3 This experiment demonstrates the importance of certain elements in healthy plant growth
4 Plants grow well in soil which contains minerals Only small quantities of the mineral are needed for healthy growth
In smaller quantities plants also need minerals such as
Magnesium Iron Calcium Sulphur
A healthy tomato plant Tomato plant suffering from potassium deficiency
